Electrical switch with rotor bearing formed integrally from contact plate



Sept. 17, 1968 N. SCHINK 3,402,268

ELECTRICAL s'w'I WITH ROTOR BEARING FORMED INTEGRALLY FROM CONTACT PLATEOriginal Filed July 2, 1964 2 Sheets-Sheet l INVENTOR William N..S'ckirzk w. N. SCHINK 3,402,268 ELECTRICAL SWITCH WITH ROTOR BEARINGFORMED' INTEGRALLY FROM CONTACT PLATE 1964 Sept. 17, 1968 2 Sheets-Sheet2 Original Filed July 2,

IIIII 'IIIIII'IIIIIIIII FIG. 11

W 5 W fw T@ t mNM mm/W/ M United States Patent 3 402 268 ELECTRICALSWITCH wITH ROTOR BEARING FORMED INTEGRALLY FROM CONTACT PLATE WilliamN. Schink, Crystal Lake, Ill., assignor to Indak Manufacturing Corp.,Northbrook, 11]., a corporation of Illinois Original application July 2,1964, Ser. No. 379,894, now Patent No. 3,329,790, dated July 4, 1967.Divided and this application Feb. 9, 1967, Ser. No. 614,998

4 Claims. (Cl. 200-11) ABSTRACT OF THE DISCLOSURE The rotor of anelectrical switch is supported at one end by a bearing comprising atubular eyelet-shaped projection formed integrally with a fixed contactplate. A plurality of contact plates are mounted on an insulating boardformed with a plurality of semi-perforated segments projecting forwardlybetween the plates, to locate the plates, and to provide for smoothmovement of the contactor between the contact plates.

Specification This application is a division of my copendingapplication, Ser. No. 379,894, filed July 2, 1964, now Patent No.3,329,790.

This invention relates to electrical switches of the rotary type. oneexample of such a switch is shown in Soreng Patent No. 2,868,906,patented Jan. 13, 1959. The switch of the Soreng patent has a rotor orcarriage which is provided with a front bearing only. No rear bearing isprovided.

The present invention contemplates the provision of a rotary switch inwhich a rear bearing is provided for the rotor. The improved stabilityprovided by the rear bearing is achieved at virtually negligible cost.

In accordance with the present invention, the rear bearing is providedby forming a projection on a contact plate fhich is disposed oppositethe axis of the rotor. The projection is preferably in the shape of acylindrical eyelet formed integrally with the contact plate. The rotoris provided with a bore or other element for rotatably receiving theeyelet.

The invention has the further objective of providing a switch in which aplurality of contact plates are mounted against the front side of theinsulating board. Semi-perforated segments are formed on the board so asto project forwardly between the plates, for locating the plates on theboard. The semi-perforated segments are flush with the plates and arearranged to provide for smooth movement of the contactor between thecontact plates.

Further objects and advantages of the present invention will appear fromthe following description, taken with the accompanying drawings, inwhich:

FIG. 1 is a side elevational view of an electrical switch to bedescribed as an illustrative embodiment of the present invention.

FIG. 2 is a rear elevational view of the switch.

FIG. 3 is a front elevational view.

FIG. 4 is an enlarged longitudinal section through the switch, takengenerally along the line 4-4 in FIG. 5.

ice

FIG. 5 is a cross-sectional view taken generally along the line 55 inFIG. 4.

FIG. 6 is a front view of the insulating board employed to support thecontact segments and terminals in the switch of FIGS. 15.

FIG. 7 is a front elevational view of a one-piece metal stamping whichis mounted on the insulating board to provide all of the contactsegments, after which the outer spider portion of the stamping istrimmed away.

FIG. 8 is a fragmentary enlarged somewhat diagrammatic sectional viewtaken generally along the line 8-8 in FIG. 6.

FIG. 9 is an elevational view of a different construction, forminganother illustrative embodiment of the present invention.

FIG. 10 is a fragmentary enlarged section taken generally along the line10-10 in FIG. 9.

FIG. 11 is a fragmentary section taken generally along the arcuate line1111 in FIG. 9.

The contact and terminal construction of the present invention will bedescribed as embodied in a rotary electrical switch 20, shown generallyin FIGS. l-3. The switch is of the general type disclosed and claimed inthe Soreng patent, No. 2,868,960, patented Jan. 13, 1959, and assignedto the same assignee as the present application. It will be seen thatthe switch 20 comprises a rotary operating shaft 22 to which a knob 24is secured. The switch may also be arranged for key operation, ifdesired. The shaft 22 is rotatably mounted in a bearing sleeve orbushing 26 which extends forwardly from the front wall 28 of a generallycylindrical cup-shaped casing or housing 30. The switch 20 is adaptedfor mounting on a panel 32 having an opening 34 therein for receivingthe bushing 26. Screw threads 36 are formed on the bushing 26 to receivea nut 38 for securing the switch to the panel 32. Within the casing 30,the switch has an insulating rotor 40 which may be made of variousplastics or other suitable insulating material. The rotor 40 has a hub42 which is suitably connected to the shaft 22 and is rotatabletherewith.

In this case, the rotor 40 carries two diametrically opposite contactors44, but the contactor arrangement may be varied to accomplish variousswitching functions. Each of the illustrated contactors 44 comprises ametal plate 46 which faces rearwardly and is in a radial planeperpendicular to the axis of the rotor 40. An inner contact point 47 andtwo outer contact points 48 and 49 project rearwardly from the plate 46.The contact points 47-49 are generally hemispherical in shape. It willbe seen that the contact points 47-49 are arranged in a triangle, andthat the plate 46 is generally triangular in shape.

Each contactor 44 has a pair of prongs 50 and 51 which project intoguide slots or openings 52 and 53 formed in the rear side of the rotor44. Thus, the contactors 44 are guided for movement from front to rear.A spring 54 is compressed between the rotor 40 and each contactor 44 andis effective to bias the contactor rearwardly, away from the rotor. Eachspring 54 is received in a socket or slot 56 formed in the rear of therotor 40.

In the illustrated switch, the contactors 44 are engageable with aninner or central contact segment 60 and five outer contact segments61-65 which are mounted to the rear of the rotor 40 and in a radialplane perpendicular to the axis thereof. The central segment 60 and theouter segment 61 are connected together and may be formed in one piece,but the other segments 62-65 are insulated from each other and from thesegments 60 and 61. The outer segments 61-65 are arranged in a circlearound the central segment 60. It will be seen that the inner contactpoints 47 on the contactors 44 are engageable with the central segment60, while the outer contact points 48 and 49 are engageable with theouter contact segments 61-65. The contactors 44 are adapted to act asbridges to complete various electrical circuits between the centralsegment 60 and the outer segments 61-65.

The segments 60-65 are in the form of metal plates mounted on aninsulating terminal board or plate 68 which is circular in shape andcloses the rear side of the casing 30. In this case, the insulatingboard 68 is secured to the casing 30 by a flange portion 70 thereonwhich is turned inwardly behind the insulating board.

The insulating board 68 may be made of a suitable insulating material,such as a phenolic plastic, for example, preferably having a surfacecoating 72 made of a heat-resistant material such as melamine plastic.The illustrated contact segments 61-65 are secured to the insulatingboard 68 by suitable fasteners which may take the form of rivets 81-85.Holes 86-90 are formed in the insulating board 68 to receive the rivets81-85. The central contact segment 60 is part of the segment 61 and issecured to the insulating board 68 by the rivet 81.

The rear ends of the rivets 81-85 project behind the insulating board 68and are employed to secure terminal lugs 91-95 to the rear side of theinsulating board. In this case, a resistor 96 is connected between theterminal lugs 93 and 95, which are somewhat longer than the others. Theresistor 96 is in the form of a coil of resistance wire. The terminal 91may be connected to the battery or other source of power, while theother terminals 92-95 may be connected to lighting circuits or the likewhich are adapted to be controlled by the switch. The illustrated switchis intended particularly for controlling the lights on an automotivevehicle, but may be used for various other applications.

Each of the illustrated terminal lugs 91-95 is bent into an L-shape toform a base portion 98 and a rearwardly projecting leg 100. In eachcase, the base portion 98 is clamped against the rear of the terminalboard 68 by the corresponding rivet. Thus, a rivet hole 101 is formed ineach base portion 98. Means may be provided to connect leads to therearwardly projecting legs 100. Thus, some or all of the legs 100 may befitted with terminal screws 102.

To prevent the terminal lugs 91-95 from turning about the rivets 81-85,the base portion 98 of each terminal lug is formed with a prong 104which projects forwardly adjacent the rivet hole 101. Some of the rivetholes in the insulating board 68 are formed with key ways or slots 106to receive the prongs 104. Thus, such key ways 106 connect with theouter side portions of the rivet holes 86, 88 and 90, as shown in FIG.6. In the case of each of the remaining rivet holes 87 and 89, a recess108 is formed in the rear side of the insulating board 68 adjacent theouter side portion of the rivet hole. The recess 108 extends only partway through the insulating board 68. Each recess 108 may be formed by adie operation in which the recess is squeezed into the insulating board68 by a die which applies high pressure to the area in which the recessis to be formed.

In this case, the central contact segment 60 is formed with an axialeyelet or bushing 110 which provides a rear bearing for the rotor 40.The eyelet 110 is cylindrical in shape and is formed integrally with thecentral contact segment 60. It will be seen that the eyelet 110 projectsforwardly into a socket or bore 112 formed in the rear side of the rotor40. The front of the rotor 40 is supported by the shaft 22 which has aportion 114 rotatably supported in a bore 116 which is formed in thebushing 26.

The contact segments 60-65 are preferably made of brass, copper or othersheet metal which is highly conductive and which is easy to stamp andform, so that the various segments and the eyelet portion may easily beformed.

In accordance with one of the important features of the presentinvention, the insulating board 68 is formed with a plurality ofsemi-perforated segments or members 121-126 which project forwardly fromthe insulating board and are disposed in the spaces or openings betweenthe various contact segments. The semi-perforated members 121-126 servethe function of positively locating the contact segments 60-65 so as toprevent them from rotating about the rivets 81-85. In addition, thesemi-perforated members provide smooth surfaces which are flush with thefront surfaces of the contact segments 60-65, to provide for smoothcontact movement between the contact segments. The semi-perforatedmembers 121-126 are preferably punched forwardly from the insulatingboard 68 by a die-forming operation. The forward displacement of thesemi-perforated members is clearly shown in FIG. 8.

The semi-perforated segments or bosses 121-125 are arranged around thecircular path which is traversed by the outer contact points 48 and 49of the contactors 44. Thus, the outer contact points 48 and 49 ridealong the semi-perforated segments 121-125 when the contact points passbetween the various contact segments 61-65. It will be seen that thesemi-perforated segment 121 extends between the contact segments 61 and62. The semi-perforated segment 122 extends between the contact segments62 and 63. The semi-perforated segment 123 extends between the contactsegments 63 and 64. Similarly, the semi-perforated segment 124 extendsbetween the contact segments 64 and 65 while the semi-perforated segment125 extends between the contact segments 65 and 61.

The remaining semi-perforated segment 126 is along the smaller circletraversed by the inner contact points 27 of the contactors 44. It willbe seen that the semi-perforated segment 126 is disposed in a notch orcutout 128 formed in the central contact segment 60.

Each of the semi-perforated segments 121-126 has a smooth front surface130 which is substantially flush with the front surfaces of the contactsegments 60-65. A recess 132 in the rear side of the insulating board 68results from the formation of each of the semi-perforated segments121-126.

In accordance with the present invention, it is preferred to employ amethod of manufacture in which all of the contact segments 60-65- areformed initially in a single piece or blank 134 which is stamped fromsheet metal. In addition to the various contact segments 60-65, theblank 134 incorporates an outer spider portion 136 which comprises acircular ring 138 extending around the outside of the blank. The spider136 also comprises a plurality of radial arms 141-149 which extendbetween the ring 138 and the various contact segments 61-65. It will beseen from FIG. 7 that each of the contact segments 61-65 is supported bytwo of the arms 141-149, except that the contact segment 64 is supportedonly by the arm 147, which is wider than most of the other arms.

The contact assembly is produced by mounting the one-piece blank 134 onthe front side of the insulating board 68. The semi-perforated segments121-126 result in the precise positioning and orientation of the blank134 relative to the insulating board. The blank 134 is secured to theboard 68 by inserting and setting the rivets 81-85. Finally, the spiderportion 136 of the blank 134 is removed by a trimming operation whichsevers all of the radial arms 141-149 along a circular trim line Thismethod of manufacture is easy and extremely economical. Nevertheless,the various contact segments 60-65 are positioned with a high degree ofprecision.

The semi-perforated segments 121-126 prevent any movement of the contactsegments 60-65 about the rivets 81-85.

In summary, the semi-perforated segments or bosses 121-126 play animportant role in the manufacture of the contact assembly, in that theone-piece metal blank 134- is precisely located and oriented by thesemi-perforated segments. After the rivets 81-85 have been set and thespider portion 136 of the blank 134 has been trimmed away along the line150, the semi-perforated segments 121-126 maintain the precisepositioning of the cont-act segments 60-65 and prevent any rotation ofthe segments about the rivets 81-85. Due to the provision of thesemi-perforated segments, only one rivet is needed for each of the sheetmetal contact segments.

The semi-perforated segments 121-126 also form slide surfaces 130 whichare flush with the front surfaces of the contact segments 60-65 so as toprovide for smooth contact movement between the contact segments. Thesemiperforated segments 121-126 virtually eliminate any roughness or anyfalse detenting action in the operation ofthe switch.

The semi-perforated segments 121-125 are disposed between the contactsegments 61-65 and are effective to minimize the electrical arcingbetween the contactors 44 and the contact segments. The semi-perforatedsegments tend to cool and extinguish the arcs which form when thevarious circuits are broken by the movement of the contactors. Themelamine plastic coating on the semi-perforated segments is especiallyresistant to the heat generated by the electrical arcs.

FIGS. 9-11 show the manner in which the present invention may be appliedto a quite different contact construction 160, comprising anarcuately-shaped insulating board 162 which supports a one-piece contactplate 164. It will be seen that the contact plate 164 comprises threecontact segments 166, 167 and 168, all of which are connected togetherelectrically by continuous inner and outer border portions 170 and -172on the plate 164. Segmental openings 174 and 175 are formed in the plate164 to define the spaces between the segments 166-168.

In accordance with the present invention, semi-perforated segments 178and 179 are punched forwardly from the insulating board 162, forreception in the openings 174 and 175'. The semi-perforated segments 178and 179 correspond in size and shape to the openings 174 and 175 andserve to locate the contact plate 174 with a high degree of precision onthe insulating board 162. The semiperforated segments 178 and 179 arepreferably punched forwardly from the insulating board 162 by adie-forming operation. It will be seen that the front surfaces of thesemi-perforated segments 178 and 179 are flush with the front surfacesof the contact segments 166-168, so as to provide for smooth contactmovement between the contact segments.

Suitable means are provided to secure the contact plate 164 to theinsulating board 162. As shown, this is accomplished by two pairs ofinner and outer tabs 181 and 182 which project rearwardly from the metalplate 164 and are bent over behind the insulating board 162. The innertabs 181 project through slots or openings 183 in the insulating board162. Notches .184 are formed in the board 162 to receive the outer tabs18 2.

An inclined semi-perforated segment 186 is formed from the insulatingboard 162 adjacent the contact segment 166 to provide a ramp, wherebycontacts may be moved in a smooth manner onto and off the contactsegment 166. The semi-perforated segment 186 slants from a level flushwith the contact segment 166 to the level of the front surface of theboard 162, as shown to best advantage in FIG. 11.

Thus, the present invention is applicable to a wide variety of contactconstructions, in which it is desired to achieve precise and positivelocation of sheet metal contact members on an insulating plate or board.The present invention has the added advantage of providing smoothcontact movement between the contact segments.

Various other modifications, alternative constructions and equivalentsmay be employed without departing from the true spirit and scope of theinvention, as exemplified in the foregoing description and defined inthe following claims.

I claim:

1. In an electrical switch,

the combination comprising a housing having an insulating board mountedthereon,

a contact plate mounted in said housing on the front side of said board,

an insulating rotor mounted in said housing for rotation opposite saidcontact plate,

said housing having means forming a front bearing rotatably supportingthe front portion of said rotor,

at contactor carried by said rotor in said housing and engageable withsaid contact plate,

and a tubular eyelet formed integrally with said contact plate andprojecting forwardly therefrom in said housing and along the axis ofrotation of said rotor and forming a rear bearing for said rotor,

said rotor having an axial bore therein rotatably receiving said eyelet.

2. In an electrical switch,

the combination comprising a housing having an insulating supportthereon,

a contact plate in said housing and mounted on said support,

a rotor made of insulating material and mounted in said housing forrotation in front of said contact plate,

said housing having a front bearing rotatably supporting the frontportion of said rotor,

a contactor carried by said rotor in said housing and engageable withsaid contact plate,

a tubular eyelet formed integrally with said contact plate andprojecting forwardly therefrom in said housing and along the axis ofrotation of said rotor,

and axial means on said rotor rotatably mating with said eyelet wherebysaid eyelet provides a rear bearing for said rotor.

3. In an electrical switch,

the combination comprising a housing having an insulating supportthereon,

a contact plate mounted in said housing and on said support,

an insulating rotor mounted in said housing for rotation in front ofsaid contact plate,

said housing having a front bearing rotatably supporting the frontportion of said rotor,

at contactor carried by said rotor in said housing and engageable withsaid contact plate,

a generally cylindrical projection formed integrally with said contactplate and projecting forwardly therefrom in said housing along the axisof rotation of said rotor,

and axial means on said rotor and rotatably mating with said projectionwhereby said projection provides a rear bearing for said rotor.

4. In an electrical switch,

the combination comprising a housing having an insulating board mountedthereon,

a plurality of contact plates mounted in said housing and against thefront side of said board,

means for securing said plates to said board,

a rotor mounted in said housing for rotation opposite said plates,

said housing having a bearing rotatably supporting said rotor,

a contactor carried by said rotor in said housing and having rearwardlyprojecting contact points engageable with said plates,

7 8 said contact points being movable along a circular path, ReferencesCited and a plurality of semi-perforated segments projecting UNITEDSTATES PATENTS forwardly in said housing from said board between saidplates for locating said plates on said board, 2,868,906 1/1959 saidsemi-perforated segments being flush with said 5 3,345,741 10/1967Relmann plates and extending along said circular path to provide forsmooth movement of said contact points LEWIS MYERS between said contactplates and along said segments. I. R. SCOTT, Assistant Examiner,

